Schistosomiasis is a disease of man and animals caused by parasitic trematodes of the genus Schistosoma. This proposal seeks to isolate, characterize, and to test experimentally potential common target antigens or antigenic determinants from various trematodes including Fasciola, Schistosoma, and Paragonimus as to their protective effect primarily to Schistosoma, and to a lesser extent, Fasciola. Monoclonal anitbodies will be developed for the identification and isolation of defined immunity antigens. Emphasis will be on the development of monoclonal antibodies against different epitopes of trematode common surface antigens. The antibodies will then be used to isolate the antigens of interest. The purified antigens will then be characterized biochemically and their protective effects will be ascertained.